Here is a wonderful explanation from movie critic Roger Ebert about the visceral feelings of "elevation" that we feel at those magic moments in life when we are observing human beings at their best. A couple of excerpts follow, but please follow this link and read the entire article:

Elevation has always existed but has just moved out of the realm of philosophy and religion and been recognized as a distinct emotional state and a subject for psychological study. Psychology has long focused on what goes wrong, but in the past decade there has been an explosion of interest in "positive psychology"--what makes us feel good and why. University of Virginia moral psychologist Jonathan Haidt, who coined the term elevation, writes, "Powerful moments of elevation sometimes seem to push a mental 'reset button,' wiping out feelings of cynicism and replacing them with feelings of hope, love, and optimism, and a sense of moral inspiration."

Studies have indicated that Elevation is triggered by the stimulus of our vagus nerve, described by Wikipedia as the only nerve that starts in the brainstem and extends down below the head, to the neck, chest and abdomen, where it contributes to the innervation of the viscera. It must be involved in what we call "visceral feelings," defined as "relating to deep inward feelings rather than to the intellect."